Peas can be germinated from March onwards and planted outside as they are surprisingly tolerant of frost. Depending on where in the country you are gardening, Peas will tolerate temperatures down to around -2, but are not happy with prolonged frost or snow. In milder parts of the country plant outside in March, in other areas under glass for planting outside in April or May.
Plant or sow about 10-15cms apart in rows which are spaced out. If planted too close together, it can aggregate mildew, which Peas are prone to later in the season. Plants which are dry are more prone, so water well and planting further apart helps the air circulation.
Peas don't like their roots being disturbed and one advantage of sowing into toilet roll holders as opposed to root trainers is that with toilet roll holders you can leave them in situ or peel away carefully, causing minimum disturbance to the roots. Keep compost moist and the Peas should germinate easily.
If germinated under glass, once the seedlings are about 15cms high, you need to harden off before planting out. It's too much of a shock to the plant to go from the protected environment of a greenhouse straight outside. Place the tray of plants outside on milder days bringing inside at night. Leave out for longer periods until the plants are outside all the time.
Peas are an ideal crop for children to grow. They germinate easily, grow quickly and can be picked and eaten straight from the pod.
In the same way as Lathyrus odoratus, the Sweet Pea, Peas put out many tendrils and if you have time, it is a good idea to thin these out a bit otherwise, towards the end of the growing season, the peas can be a bit of a tangle which reduces growth and cropping. Apart from this, Peas don't need any real maintenance except to improve the crop ensure the crop does not run short of water once the flowers appear. It's always a good idea if buying seed or plants to select those with RHS merit award, which is an indication of best performance.
There are first early, and second early, varieties of peas designed to fruit at different times.